Large-scale HIV vaccine trials to start in SA

HIV in Africa South Africa's first large-scale HIV vaccine efficacy trial will start next year at five clinical sites around the country.

Representatives from the HIV Vaccine Trials Network and the SA Aids Vaccine Initiative remained tight-lipped on details of the number of subjects and the locations of the trial sites, saying an announcement would be made in January.

But principal investigator at the Desmond Tutu HIV Centre at UCT, Linda-Gail Bekker, said the trials would test the efficacy of a subtype B HIV vaccine on South Africa's predominantly subtype C sufferers.

Each HIV-infected region of the world tends to have a predominant genetic subtype of the virus.

"We're at a very exciting point at the moment," Bekker said. It was difficult to find concentrated populations of people at risk of contracting HIV in other countries - unless one used sex workers, for example - which is what made SA such a "hot spot" for efficacy trials. In some local communities, the prevalence of HIV was one in three people.

Bekker added that in the communities where they worked, there was a sense of wanting to take part in the trials. Interestingly, she added, while many of the clinics were mostly visited by women, there were more men in the vaccine discussion groups - perhaps because taking part in a vaccine trial was seen as more "macho".

As far as the vaccine was concerned, "first prize", as Bekker put it, would be for the vaccine to abort the infection before it took hold in the cells. But, more likely, the vaccine to be tested next year would in some way modify the infection once it did take hold by pushing the viral "set point" as low as possible which would delay the onset of symptoms and possibly make the virus less potent.

Alternatively, the vaccine might reduce that initial peak point when the probability of transmission is much greater.

Bekker said she was pushing to focus on children and adolescents in future vaccine trials. There were almost two billion people between the ages of 10 and 24 in the world, 10 million of whom were living with HIV and two thirds of those were in sub-Saharan Africa.

Every 14 seconds a person in the 10-24 age group became infected. The rates of new infection among adolescents in South Africa were increasing as the age of sexual debut - typically between 14 and 16 - was getting lower and testing for this group was urgently needed.

source The Cape Times